Unable to cancel/edit class instance

I have a yoga studio who uses Squarespace Scheduling for enrollment in their classes. They have a weekly class on every Wednesday, but this week they need to cancel the class. I have tried deleting the instance, but when I type "DELETE" and click "OK", I am booted out of scheduling and sent back to the home page and home screen of my dashboard, and the class has not actually been deleted.

I tried to edit the class from 100 allowed slots to 0, but after doing that I get a message that says that the class was "successfully added" to the calendar; checking the class details still shows 100 available slots.

Is there a system-wide glitch happening right now? This process usually works for me.

I'm also having this same issue. Any resolution?